Equal parts hydroponic garden, aquarium, and interactive art, the Farm Fountain is an experiment in self-contained, indoor ecosystem design created by artists Ken Rinaldo and Amy Youngs. The idea is that you can raise edible fish and cycle their waste nutrients through a hanging garden which filters the water before returning it to the aquarium.

Their 4th generation Farm Fountain is currently on display at the Te Papa Museum in New Zealand until January 2009. From the Farm Fountain website:

This project is an experiment in local, sustainable agriculture and recycling. It utilizes 2-liter plastic soda bottles as planters and continuously recycles the water in the system to create a symbiotic relationship between edible plants, fish and humans. The work creates an indoor healthy environment that also provides oxygen and light to the humans working and moving through the space. The sound of water trickling through the plant containers creates a peaceful, relaxing waterfall. The Koi and Tilapia fish that are part of this project also provide a focus for relaxed viewing.

The plants we are currently growing include lettuces, cilantro, mint, basil, tomatoes, chives, parsley, mizuna, watercress and tatsoi. The Tilapia fish in this work are also edible and are a variety that have been farmed for thousands of years in the Nile delta.

A Basic Stamp program controls the pump mechanism, allowing the plants to be watered at regular intervals for a set period of time. Depending on available natural light, supplemental lighting can be provided by a combination of fluorescent and grow-spectrum LED lighting, switched from a standard light timer. Ken and Amy worked out a lot of the details during the construction of their 3rd Farm Fountain design (pictured above) and they've assembled a how-to instructional gallery which you can use to design your own Farm Fountain system.

There are a lot of external inputs required to keep the ecosystem healthy for a long period of time including fish food, PH and nitrate monitoring, and general gardening tasks. Once you've gotten accustomed to it, though, it's probably not much more work than maintaining a lawn, and a lawn can't give you tomatoes in the middle of winter.

Farm Fountain - a sculptural ecosystem you can eat

Just because it's hot doesn't mean the kids have to stay indoors in the A/C. There are a number of worthwhile summer projects, but the KidWash looks like it has a particularly high fun/effort ratio. A trip to the hardware store for some PVC and mister jets and you can give the Wii a run for its money next weekend.

I headed down to the PVC section of the local home improvement store to pick up supplies. While browsing the adjacent sections for interesting stuff I noticed the micro-irrigation section and inspiration struck: KidWash with mister jets!

The modification worked great. We turned it on and kids from up and down the block started showing up to help with the testing. It's a lot of fun on foot, but my kids also get a blast out of riding their bikes through it.

This would be great to combine with a DIY visqueen slip and slide.

KidWash 2 : PVC Sprinkler Water Toy

When Motion detects movement, it archives a photo of the event and has the option of triggering an external script. Shantanu combined this with a simple curl command that will ping your Twitter account when a motion event occurs. The end result is a tweet that tells you that motion was detected and checking Motion's integrated mini-http server will allow you to see if it's a false alarm or view the intrusion in real time.

I'm going to set this up at work so I can track down who keeps running off with my red stapler.

Keep Tab On Home Security With A Webcam And Twitter
Motion

It seems like I end up updating my laptop every couple of years, but as cool as new hardware is, sometimes the challenge of finding a new use for the old machine is more interesting. The iNoteBook mod is a classic example, transforming a broken, screenless iBook into a stealth desktop machine.

What's your favorite laptop reuse project? If you've got one, please share in in the comments.

The iNoteBook

Hackszine reader clickthegoogleads wrote to us about a set of Wiimote controlled curtains:

The curtain control system is an existing system from Goelst and is called "G-Rail 6200". Normally it is controlled by infrared or wallswitches. However, it can also be controlled with a CAN bus. I used this CAN bus to interface with an old PC. ... GlovePIE has no function to send messages to a CAN bus. So I started up my good old visual basic and made a little program that handles the CAN messaging. In the first version I used the keypressed event. I made a GlovePIE script that sends out keyboard keys when the Wiimote has a certain orientation and voila... L is for left, R is for Right and S is for Stop.

Is there anything that Wiimote can't do?

Wiindow Curtain Control - Link
GlovePIE - Link

With Monday finally wrapping up, it's time to start thinking about next weekend. Why not spend it Twitter-enabling your house plants?

Botanicalls Twitter answers the question: What's up with your plant? It offers a connection to your leafy pal via online Twitter status updates that reach you anywhere in the world. When your plant needs water, it will post to let you know, and send its thanks when you show it love.

I've managed to make it through the winter with only two plant casualties so far. There isn't a whole lot I can do about the scarcity of light in Minneapolis, but with a little Arduino hacking I could at least remove watering issues from the equation.

Botanicalls Twitter - Link

An anonymous reader requested a hack today to solve a particular kind of kitty problem. Specifically, the reader wants to know if there's a way to have a cat door that grants access to particular cats while restricting entry or exit for others. Not being a cat owner, I don't follow cat electronics too closely, but I have heard of a project or two that are similar in nature, and I'd like to open this up for further discussion in the comments.

The photo above is from the Flo Control project. This cat, Flo, had a nasty habit of bringing in dead mice to the house. Her owner created a computer controlled system that captures an image of the cat as it approaches the door. The PC does some image recognition to determine if the cat's silhouette is atypical (ie. carrying something nasty) and only unlocks the door if the cat is sans-mouse.

One element that's used in the Flo Control setup is a cat door product made by Cat Mate. They make a few different models of cat doors that require your cat to wear a special collar to be allowed through. These are typically operated by a magnet or infra-red beacon in the collar which is able to mechanically or electronically unlock the door. My guess is that something like this will probably will do the job, but if your neighbors start doing the same thing, there's nothing to keep other cats with a collar from getting in.

A more interesting idea is to use RFID to uniquely identify a particular cat and grant access accordingly. There's a commercial product called Pet Porte that is able to do this with the RFID chip implants that some owners are sticking on their animals these days, but I figure it might be more fun to make your own, perhaps using a tag on a collar.

There are a number of RFID sensors for the Arduino and Basic Stamp microcontrollers. It'd be straightforward to program one of these to accept specific RFID tags and then trip the lock switch in a slightly hacked Cat Mate door. The only problem I see is devising a collar that wouldn't bug the cat and would also place the RFID tag in close enough proximity to the reader. Any readers out there with thoughts on this?

The Flo Control Project - Link
RFID Enabling Your Front Door - Link
Using the Arduino with the Parallax RFID reader - Link

It's hard to find a good place to store your bikes when you're an apartment dweller. Here's a nice looking bike rack made from a few cheap Ikea shelving parts.

All you need to get from ikea is one stolmen post, two brackets and four hooks. you'll also need some screws and some aluminium 20x20mm square pipe, maybe some foam rubber.

I think I'll give this a try in my garage to clear up some needed floor space.

Stolmen Bike Rack - Link

Before you buy a replacement battery for your dead Roomba, you might want to consider rebuilding the pack yourself. You can get a couple of 6 cell Sub-C NIMH packs for less money and more amp hours than the stock battery.

I've been wondering whether it would be economical to just rebuild the battery pack, versus buying a new one. From the looks of it, all it takes is 12 NiMH cells, and from the looks of the case, it looks to be C-Size form factor. For less than $36, I can pick up 12 4500 mAh C cells. I can see iRobot has tried to prevent people from doing this by using TRIANGLE bits for their battery cases, but that's simple to get through.

To remove the triangle bits, just find a small flathead screwdriver that you can wedge in nicely.

Rebuilding a Roomba Battery for Less - Link, Photos

Sometimes the solution for an everyday problem is so simple it takes thousands of years for someone to fail to overlook it. Take this clever concept for a flower pot that leans over to signal you when your plant needs watering. Jonah @ Makezine writes:

Unlike some plants that call you on the phone when they are thirsty for water, The "Roly-Poly Pot" concept by Samgmin Bae begins to tilt over when its water levels are low, thus serving as a visual reminder of their thirst. Each pot can be adjusted to work with the plant's watering needs and schedule.

Roly Poly Pot - Link

Here's a little howto on building a low-RPM generator from scratch. I assume that not all of you have extra hamsters lying around to power your night lights, but a similar design could be used for creating a small generator for wind or other energy sources.

Though it's hard for the hamster to make higher voltages with his low-rpm wheel, he has torque to spare. 2 LEDs are barely taxing him......we are drawing only about 30 milliamps into the LEDs at Skippy's top speed. If we add more electrical load to the circuit, he could make more power, with a resulting increase in physical resistance on the wheel---like running uphill. We have yet to try small incandescent flashlight bulbs in the circuit--something that draws more power and makes more physical resistance against the wheel spinning. We did try more LEDs -- he had no trouble lighting up 6 of them. Next we plan to try an array of low-voltage incandescent flashlight bulbs to get optimum power output without tiring Skippy out too much. DanF is guessing that Skippy is good for 200 milliamps without tiring...

One cool thing is that the author uses a bicycle computer to track the hamster wheel's average and top speeds over time. This is a nice tool to have if you're trying to monitor and optimize the environment for your generator setup.

Hamster-Powered Night Light - Link

If you have an older toilet with a 5 gallon tank, there's an old trick that you can use to convert it to use less water. By simply filling a half gallon container and submerging it in the tank, you can cut your toilet water usage by 10 percent or more. Lifehacker's Gina T. points us to a wikiHow artcile on the topic:

If you, like most Americans, flush 5 times daily, your family of 5 will save 350 gallons (1325 liters) of water every month [2]. These savings will significantly cut your water bill, too.

Adjusting the tank volume will affect your toilet's ability to flush more, uh, serious business, so your mileage may vary. A lot of folks have a second bathroom that's used more often for lighter work, in which case this hack could save quite a bit of water over a year's time.

How to Convert Any Toilet to a Low Flush Toilet - [via] Link

I bought some GE bulbs that are supposed to work in ceiling fans, but they flicker and flash big time. I was able to get them to stop, oddly enough, by activating the dimmer and finding a sweet spot for the settings, but that was a hassle. So I did some trial and error tests and as you can see in the embedded video, 3 CF bulbs + 1 incandescent is the magic recipe.

I think the problem is in the fine print that says the bulbs aren't designed for dimmer switches; even though the lights are set on full power by default, I think there's something in there that interferes. So a future project might be to remove the dimmer from the fixture, get a new fixture, or find a CF bulb that supports dimmers and ceiling fans.

This looks almost like having your own biosphere. Earthships are a pretty unique form of sustainable architecture that are compatible with a wide range of environments around the world. Each home is custom built to fit its particular environment, but there are a few things they all seem to have in common:

• They are built from primarily reused materials. The load-bearing walls are actually constructed from old tires packed with dirt, and recycled cans and bottles are used as filler throughout non load-bearing concrete structures.
• Passive-solar energy is used for heat regulation. They are smartly placed semi-embedded in a hill with south facing windows. This helps regulate the temperature even through drastic external temperature changes.
• Off-grid solar and wind power are used to supply all electricity needs.
• A rainwater capture system provides drinking water, which is then recycled into greenhouse water, then to toilet/waste water, before finally exiting to a self contained septic system.
• The south side of the home functions as a greenhouse, which assists with water treatment as well as aesthetics and supplemental food.

I'm pretty sure this wouldn't fly in the middle of a metropolitan area, but I love it all the same.

Earthship Biotecture - [via] Link

A couple weeks ago I heard about a study which showed that nuking a grungy sponge for 2 minutes was effective at sterilizing it. This was quickly followed by reports of a number of small fires involving dry sponges. Lesson learned: wet your grubby sponges before superheating them.

There are a number of interesting things to do with the household microwave. Of course, there are a number of materials which will spark or ignite, but my personal favorite is David Reid's method for casting small amounts of soft metals like bronse, silver, and gold. On the less dangerous side, there's also the strange and unexpected growth phenomena of marshmallows or bars of soap, though I'm not sure what this is good for besides entertaining the kids with Peep battles.

Finally, you can do a lot of conventional things with a microwave as well. The guardian recently released a top 10 list on the subject. There are hacks for softening citrus fruits for juicing, heating up plates for serving, and sterilizing potting soil before planting seedlings.

What's your favorite microwave hack? Let us know in the comments!